Electric incandescent lamp



Feb. 23, 1937. w. HONING ET AL ELECTRIC INCANDESCENT LAMP Filed Aug. 8, 1934 [NI/ENTER 5 W22 HEL MHUNJNE GI LLS' UUDflEA/ZALNS BY fi/ 1 I4 I [K AT TURNEY ETED STATES ELECTRIC HNCANDE SCENE? Wilhelm Honing and Gillie Oudemans, Eind= hoven, Netherlands, assignors to General Electric Company, a corporation of New York Application August 8, 1934, Serial No. 739,039

- In Great Britain August 117, 1933 3 Claims.

Our invention relates to electric incandescent lamps and has for its object to provide an improved lamp of the double filament type for use in a vehicle headlight.

According to our invention, the lamp com prises a filament located therein so as to be at the focus of the headlight reflector, a second filament parallel to the lamp axis but spaced therefrom, and a V-sectioned screen or trough,

preferably of dull or non-reflecting material, cooperating with said second filament.

For a further understanding of the invention, reference may be had to the drawing, in which Fig. l is a side elevation of a lamp comprising our invention; Fig. 2 is a front end view thereof; and Figs. 3 and 4 are diagrams of beams produced by the screened filament.

Referring to Figs. 1 and 2, the lamp comprises a base In and a bulb I I having a pair of filaments l2, l3 sealed therein. The filament l2 lies on the longitudinal axis of the lamp and is located therein so as to be at the focus of the usual parabolic reflector of the headlight into which the bulb is inserted when in use. The second filament I3 is parallel to, but spaced away from, the said axis of the lamp. A V-sectioned screen or trough I4 is placed around the filament l3 and has its upper edges in a plane substantially at the longitudinal axis of the lamp. The said trough is preferably of a dull or non-reflecting material and is mounted at its rear end on the end of a leading-in wire l5 which extends forwardly into the bulb from the press portion [6 of a stem tube H. The filament i2 is mounted on the ends of a leading-in wire l8 and a short vertical wire l9 which is attached to the leading-in wire iii. A third leading-in wire extends from the stem press l6 forwardly beyond the edge of the screen or trough'H, then upwardly, and then back and down into the interior of the said trough H. The filament I3 is attached to the end of said leading-in wire 20 and to the rear end of the trough It or the leadingin wire l5. 7

With the arrangement shown in Figs. 1 and 2, when the filament I2 is rendered incandescent the lamp provides a full driving light while when the filament I3 is rendered incandescent the lamp produces a non-glare beam below the hori zontal having the form shown inFig. 3. By

tilting the trough l4 slightly, the non-glare beam the vehicle and diminish the amount of light projected to the off side, i. e., in the direction of on-coming vehicles. The beam shown in Fig. 4 is shown as swung to the left or clockwise in accordance with foreign practice, but it will be understood that the said beam would be swun or rotated in the opposite direction to conform to the practice in this country.

While the filament l2 is'shown extending axially it may have a V-shape, the center of which lies in the axis of the lamp and the focus of the reflector, or it may extend across the bulb with its center point in the axis of the lamp and in the focus of the reflector.

What we claim as new and desire to secure by Letters Patent of the United States is:

1. An electric incandescent lamp for use in a vehicle headlight comprising a bulb, a filament disposed therein substantially at the longitudinal axis of the lamp, a second filament extending parallel to thesaid axis but spaced therefrom and displaced longitudinally from said first filament, and a V-sectioned screen or trough extending longitudinally of said lamp and surrounding said second filament, the upper edges of said screen or trough being located in a plane substantially at the said axis of the lamp, and said second filament being located wholly within said trough.

2. An electric incandescent lamp for use in a vehicle headlight comprising a bulb, a filament disposed therein substantially at the longitudinal axis of the lamp, a second filament extending parallel to the said axis but spaced therefrom and displaced forwardly along said axis from said first filament, and a V-sectioned screen or trough extending longitudinally of said lamp and disposed under and surrounding said second filament, said second filament being located wholly within said trough.

3. An electric incandescent lamp for use in a vehicle headlight comprising a bulb, a filament disposed therein substantially at the longitudinal axis of the lamp, a second filament'extending parallel to said axis and located below said axis and ahead of said first filament, and a concavenon-reflecting trough longitudinally coextensive with and located under said second filament, said second filament being located wholly within said trough;

WILHELM HONING. GILLIS OUDEMANS. 

